Dimethyl carbonate (DMC) is an organic compound with the formula OC(OCH3)2. It is a colorless, flammable liquid. It is classified as a carbonate ester. It is useful as a methylating agent and as a solvent that is exempt from classification as a volatile organic compound (VOC) in the United States. Dimethyl carbonate is often considered to be a green reagent by minimizing the use and generation of hazardous substances. Dimethyl carbonate's main benefit over other methylating reagents such as iodomethane and dimethyl sulfate is its much lower toxicity and its biodegradability.
DMC has grown in popularity and applications as a replacement for methyl ethyl ketone, tert-butyl acetate, and parachlorobenzotrifluoride. It has an ester or alcohol like odor, which is more favorable to users than most hydrocarbon solvents it replaces. DMC has an evaporation rate of 3.22 (butyl acetate=1.0), which slightly slower than methyl ethyl ketone (MEK) (3.8) and ethyl acetate (4.1) and faster than toluene (2.0) and isopropanol (1.7). It has solubility profile similar to common glycol ethers, meaning DMC can solve most common coating resins. Hildebrand solubility parameter is 20.3 Mpa and Hansen solubility parameters are: dispersion=15.5, polar=3.9, H bonding=9.7. DMC is partially soluble in water up to 13%, however DMC has hydrolyzed in water based systems over time to methanol and CO2 unless properly buffered. DMC is a flammable liquid that has a flash point of 17° C. (63° F.) making it safer than acetone, methyl acetate and methyl ethyl ketone from a flammability point of view.